Through this study, we have a better understanding of history. (Amendment: Delete "manufacturing" or "passing")

2. Word repetition:

After a whole day's exercise, he was black and blue all over. (Revision: "All over" and "All over" are repeated, the latter is a word, and the former is deleted)

3. Improper collocation of words:

Everyone sang many songs and dances at the class reunion. (Revision: Dancing is not worthy of singing, and many dances have been performed)

4. Inconsistency:

I don't think he will come back today. (Revision: Uncertainty is followed by definite tone. According to the semantics, it will definitely be deleted)

5. Incomplete ingredients:

According to his suggestion, we quickly solved the problems in the project. (Revision: The first sentence lacks objects, suggestions and methods. )

There are also mixed sentences, improper related words and punctuation errors.